I've dug up some commentary on Greenland air attacks.
II/KG40 Kondor FW200 aircraft scouted potential U-boat bases along Greenland coast from m10 February 1941
In 1942, a German weather station established in Hansa Bay on Sabine Island (74'40N.) on August 26 operated until it was so badly bombed by U.S. aircraft from Iceland on 25 May 1943 that it was destroyed and abandoned.
Also the US Coast Guard Cutter North Star during 1943 was attacked by a Ju-88 off Jan Mayen Island on 20 July. On the North Star website it also notes that USCGC Northland was attacked by German planes on 15 July. At Eskimones about the same period German anti-aircraft guns drove off US aircraft.
NORTH STAR REMEMBERED
At least one Ju-290 is known to have made a flight to Greenland. 3 June, 1944 there was a harrowing rescue off the Shannon island of Greenland by II/FAGr 5, Ju 290-flown by Hauptmann Emil Sachtleben and crew.The aircraft landed on ice at Nordenskjörlds Bugt and picked up the 26 man crew of weather ship WBS 2 Koburg and flew unmolested back to Vaernes, Norway
For Ju-88 aircraft to be operating near Greenland seems a bit amazing for me unless they could land and refuel there.
Air Marshal Erhard Milch wrote in his memoirs about use of Greenland as a refuelling stop for a planned aircraft attack on New York, so I wondered whether anyone could add to the picture please?
I've also learned that the He-177 had a ferry range of about 5000 miles and in addition to installed tankage of 10,400 litres could carry another 8,000 litres in drop tanks under it's wings (something I had not realised previously)